1. Field of the Invention
The present invention relates to mixtures of reactive dyes, which are particularly suitable for dyeing fabric materials. They display good build-up, wash fastness, and levelness; especially low nylon cross-staining in blended and interwoven fabrics.
2. Description of the Related Art
To date it has been difficult to find a single reactive dye which displays good build-up to heavy black shades. In order to gain good build-up in black shades, a reactive dye composition, which contains a number of reactive dye components, has been used.
One black reactive dye (for example, the following formula (I) black reactive dye) as the major component is usually mixed 
with red, orange, yellow or other shade reactive dyes to yield black reactive dye compositions.
Black reactive dye compositions are already known from Japanese Patent Laid-open No. 58-160362, 63-178170, 1-315469, 2-73870, 2-202956, 8-104822, and 8-253697, and U.S. Pat. Nos. 5,445,654, 5,611,821, 5,780,602, 5,849,887, 5,931,974 and 6,127,700.
In order to achieve high quality fabric, a blended or interweave fabric, which contains two different fibers, has been produced and sold in the market.
When dyeing the blended fabrics, problems can be encountered in off-tone dyeing because different fibres have different affinities for the dyestuffs. Especially when dyeing nylon/cellulose blended fabrics, it is difficult to get a low nylon cross-staining product. Therefore it is necessary to select appropriate dyestuffs when dyeing blended or interwoven fabrics.
There are many black reactive dye compositions which can be chosen in the market. However the black dye compositions with little nylon cross-staining always show poor properties in levelness and build-up. Conversely, black dye compositions with good properties in levelness and build up always stain nylon badly.
Therefore, there is a strong demand for a reactive black dye composition having good dyeing properties and low nylon cross-staining.
It is one object of the present invention to provide a reactive black dye composition that is suitable for use in exhaustion, printing, continuous dyeing or discharge printing of fibers to provide good dyeing properties.
Other objects of the present invention are to provide a reactive dye composition, which has good build-up properties, wash fastness, wash-off, levelness and low nylon cross-staining of blended or interwoven fabrics.
The reactive dye composition of present invention comprises: one or more, such as one, two or three, disazo dyes conforming to component (A), one or more, such as one,two or three, disazo dyes conforming to component (B) and optionally one or two monoazo dyes conforming to component (C).
Component (A) is selected from disazo dyes which may be represented by formula (I) to formula (III), 
wherein Y is xe2x80x94CHxe2x95x90CH2 or xe2x80x94C2H4W, W is a leaving group which can be eliminated by a base; R1, and R2 are each independently hydrogen, methyl, ethyl, methoxy, ethoxy or sulfonic acid, preferably hydrogen or methoxy, and most preferably hydrogen. The leaving group W is for example, xe2x80x94Cl, xe2x80x94Br, xe2x80x94F, xe2x80x94OSO3H, xe2x80x94SSO3H, xe2x80x94OCOxe2x80x94OCH3, xe2x80x94OPO3H2, xe2x80x94OCOxe2x80x94C6H5, xe2x80x94OSO2xe2x80x94(C1-C4-alkyl) or xe2x80x94OSO2xe2x80x94N(C1-C4-alkyl)2. W is preferably xe2x80x94Cl, xe2x80x94OSO3H, xe2x80x94SSO3H, xe2x80x94OCOxe2x80x94CH3, xe2x80x94OCOxe2x80x94C6H5 or xe2x80x94OPO3H2, more preferably xe2x80x94Cl or xe2x80x94OSO3H and, particularly preferably, xe2x80x94OSO3H.
Component (B) is selected from the reactive disazo dye which may be represented by formula (IV) to formula (XI), 
wherein Y, R1, and R2 are defined as the above; R3 and R4 are each independently hydrogen, methyl, ethyl, methoxy, ethoxy or sulfonic acid, preferably hydrogen or methoxy, particularly preferably hydrogen; R5 is amino, xe2x80x94NHC2H4COOH or xe2x80x94NHCOCH3; R6 is methyl, ethyl, propyl or carboxylic acid; R7 is amino, xe2x80x94NHC2H4COOH, xe2x80x94NHCONH2 or xe2x80x94NHCOCH3; R8, and R9 are each independently hydrogen, amino or sulfonic acid; and R10 is xe2x80x94CH2SO3H or xe2x80x94CONH2.
Furthermore, the reactive black dye composition of the present invention can contain component (C) with at least a reactive monoazo dye of formula (15), (16) or (17). 
The dyestuffs of the present invention all contain anionic groups, such as a sulfonic acid groups: for convenience they are depicted as free acid in the specification. When the dyestuffs of the present invention are manufactured, purified or used, they exist in the form of water soluble salts, especially alkaline metallic salts, such as sodium salts, potassium salts or ammonium salts.
The ratio of each dye component can be changed over a wide range. In general, the minimum relative weight percentage for each dye component is 3%, and the maximum relative weight percentage is 90%. The dye composition of the present invention preferably contains component (A) 30xcx9c80% by weight, component (B) 25xcx9c75% by weight, and optionally component (C) 0xcx9c45% by weight.